Electronic fuel injection (EFI) is one of the most important breakthroughs for improving fuel consumption, pollution controls, increased power for smaller engines and for vehicles in the past fifty years. A much more precise fuel mixture is delivered into the cylinders than with even the most sophisticated carburetors over the entire engine speed range. Carburetors are set for the correct fuel mixture at one given engine speed but when the engine runs at a lower or higher speed, the mixture is no longer correct. With electronic fuel injection, the fuel is supplied to the injectors at a constant pressure and the injectors open and close at a controlled frequency and pulse width. This frequency and pulse width is controlled by an electronic controller. The electronic controller knows the speed at which the engine is running, as well as other pertinent factors, and can therefore change the frequency and pulse width sent to the coils of the fuel injectors to control the fuel mixture at the optimum amount for any given engine speed and situation.
Electronic fuel injection systems are very efficient and dependable, but suffer from one main problem. Fuel injectors should spray the fuel creating a mist of gasoline which then mixes evenly into air in the intake manifold or in the throttle body of a gasoline engine. Over time, the nozzles of the fuel injectors acquire a build-up of deposits at the output orifice. These deposits prevent a clean spray and cause a partial spray along with dripping of fuel. This dripping prevents the fuel from mixing with the air. The result is poor power, poor performance and increased fuel usage.
The deposits on fuel injectors come mainly from compounds and impurities in gasoline. Gasoline is composed of many different hydrocarbons, including olefins, which are heavy, waxy compounds. When the engine is shut off, a drip of gasoline often forms on the tip of the injector. Because the engine is hot, the volatiles in the drip of gas evaporate quickly, leaving olefin and other residue and because the engine is off, there is no cooling air flow through the ports and no fuel flow through the injectors to wash it away. Consequently, heat bakes the olefins into hard varnish deposits. Over time, these deposits can build up and clog the injectors or leave a crusty residue on or around the output orifice of the injectors. This buildup causes uneven spray or even dripping of fuel which will not evaporate into the gas-air mixture, thus causing poor performance.
Since the accumulation of these deposits is to be expected, detergents are added to gasoline to help keep the injectors clean. These detergents are typically successful in keeping the injectors clean. But lower quality gasolines contain less or weaker detergents which may allow more deposits to occur and grow. Also, when a driver makes a lot of short-trips, the deposits may can build up faster than the detergents can wash them away.
Commonly used deposit-control additives include polysibutylamine, polyisbutylene succinimide and polyisobutylene phenylamine. But these same additives can cause other issues such as a build up on intake valve stems which may cause them to stick. To prevent this, additional additives called “fluidizers” can also be added to the fuel. But, these can in turn, cause the formation of combustion chamber deposits that raise compression and the engine's octane requirements.
One of the best additives is polyetheramine, which keeps injectors, valves and combustion chambers clean without the help of any additional fluidizers. However polyetheramine is twice as expensive as the fluidizers. Experts recommend that about 1,000 parts per million (ppm) in the fuel is required to do a good job. This concentrations costs the gasoline supplier less than a penny a gallon. But, as might be expected, it is estimated that 85% of the gasoline being sold contains only one-tenth of the recommended dosage, or only 100 ppm of additive. Consequently, using cheap gas contributes to the formation of injector deposits.
Aside from these deposits, the fuel injectors can get clogged up by debris and impurities. Although gas and diesel tanks at service station use filters, anytime a tanker truck transfer fuel into a storage tank the tank is stirred and any sediment or water normally lying in the bottom of the tank below the suction line to be distributed within the fuel. Debris from the tank can then be pumped into the fuel tank of a vehicle. Fuel filters catch the majority of impurities but a small amount may make it past the filter. If there is water in the fuel system, corrosion can happen within the lines and fittings of the fuel system. This corrosion can cause debris to be jammed in the injectors.
Therefore, it is apparent that while electronic fuel injection is superior to older gasoline delivery systems in internal combustion engines, there will continue to be inherent problems with such systems.
Most systems today utilize a solvent applied to the fuel tank of a vehicle of a cleaner system applied to the fuel line of a vehicle to enable the vehicle to run and pump the fuel through the filter system.
The instant invention is a pneumatic and hydraulic using alternating air and liquid pulsed cycles for cleaning and reconditioning expensive fuel injectors removed from vehicles at scrap yards and reused where vehicles may set for an extended period of time and lack of use of the injectors allows the deposits to dry or harden during nonuse. Conventional fuel cleaners can not be circulated through the fuel system in vehicles which no longer run requiring that the injectors be removed to clean or recondition them prior to reuse. The hardened deposits are stubborn to remove and conventional systems fail to provide the requisite performance required from the injector.